This error usually occurs when you install the CS-Converter server application to the wrong web site.
To resolve this issue you must first uninstall the CS-Converter server application (CSTFS-WS). Next, re-install the CS-Converter server side, making sure that it is installed to the Team Foundation Server site and do not change the default value of the virtual folder.
For more help with installing the server side refer to Server Side Installation in the User's Guide.